Means for securing spaced air-core coils



Oct. .12, 1943. K c ows y 2,331,384.

MEANS FOR SECURING SPACED AIR-CORE COILS Filed Dec. 6, 1940 INVENTOR KURT FLACHOWSKY ATTORNE Y Patented Oct. 12, 1943 Kurt Flacliowsky; Berlin, Germany; vested in the Property Custodian Application December 6, 1940, Serial No. 368,867

Germany May 22, 1939 '4'Clajm'S. (01. 175 359) This invention relates to a new and useful arrangement of securing the conductor turns of an inductance coil for a radio frequency oscillation system.

An object of this invention is to reduce the losses in coils which are employed in ultra-high frequency circuits and to provide an improved simplified coil mounting.

With a view to diminishing the losses and to facilitating the technology of producing on a large scale production of coils having similar properties for radio frequency circuits, it, has become general practice in the prior transmitter art using short and ultra-short waves, but also inside the mediumand long-wave bands for reasons of larger power, to employ preferably unsupported air-cored coils consisting mostly of conductors of circular cross-sectional form, although fiat conductors are also used, the coils being cylindrical in shape and also of spherical (variometer) form.

According to the size of the coil and the accuracy required in spacing the constituent turns or spires of the coil apart to secure the proper pitch, four, six, eight or even more radio frequency ceramic supports or pillars are placed circularly around the coil. Bi-partite retaining members are used one end of which is clamped on a convenient point of the supporting column or rod, while the other end grips the turn of the cell at the supporting point. Where the interturn spacing of the coil is small, it has heretofore been customary to support in a way as stated each nth turn, while the interposed or intermediate turns were held in spread-apart relationship by comb-like insulation spacer pieces inserted between the turns, these spacers being secured, for instance, between two adjacent clips. It is also known in the art that the supporting rods, themselves may be notched or recessed comb-fashion, with the various turns of the coil being fitted into these slots. In the case of stationary transmitters and small inter-turn spacings, the use of greater numbers of supporting rods has been found necessary, with the supporting points of the turns coming to lie along a helical line on the coil, to the end of diminishing the loss of space due to the supporting clips.

These supporting means known in the art and used in practice have the following drawbacks:

(1) The coil winding or the turns thereof, whether clips or rods consisting of radio frequency ceramic material with comb-like notches are used, can never be so lodged that they come fully to bear in the slots, and this is liable to cause corona evenifthe edges are rounded or curved, or there is caused thermal overloading of the ceramic material.

(2) The use of great numbers of supporting uprights or rods is not desirable in the case of transportable transmitters for reason of undue Weight.

(3) For each and every cross-sectional form of the turns or spires a distinct supporting clip is needed; also, for each interturn spacing and for the various lengths of the coils distinct supporting rods are required,

(4) The limit for the smallest inter-turn distance, in the clip-type construction, is still far too high as compared with the spacing obtainable for notched or comb-type supporting rods.

Now, to obviate these difficulties, the invention creates 'a'supporting arrangement which may be standardized and which insures a simplification and improvement in construction and saving in cost and in weight. The supporting means of the invention consists essentially of a bi-partite clamp member having openings facing the coil to be supported for inserting a U-shaped clip spring and recesses for the insertion of a small number of comb-shaped supporting members between pairs of clips. The clips are springy, roughly U-shaped staples the limbs or legs of which are adapted to be inserted into the openings of the clamp member.

The curved portion of the U-shaped clip is adapted to the gauge or thickness of the concluctor of the coil so that for clips of different construction, one and the same size of clamp member is usable.

The invention is illustrated by an exemplified embodiment shown in the appended drawing. Fig. 1 shows an elevation of the new securing means, while Fig. 2 is a top view thereof.

The constituent turns of the coil 0. are supported and held in correctly spaced relationship and accurate position by means of insulating uprights or rods b mounted adjacent to the coil, the rods being fitted with clamp members 0 for this purpose, the material of which may be either insulation or metal. The clamp members consist of two parts being united by screws d. The clamps c on the side thereof opposite to or facing the coil a have projections e with insertion holes h at right angles to the rod 27. Into these holes are introduced the legs 2" of the springy metallic clip 1' after the latter has been mounted on the conductor a. The clip 1' thus is made flat in the curved portion, while the legs are of circular cross-sectional form.

place a number of clips of dissimilar size may be used. Hence, replacing the clamps or changing the supporter rods is now no longer necessary when the diameter of the coil conductor is altered.

To support the turns of the coil between a pair of clamp members the insulating combshaped spacer pieces r are provided with circular recesses which are formed at s in the prongs thereof for supporting the conductor a thereto.

The said spacers T have projections t at their ends which fit into recesses o of the clamps e. Replacement of the comb-shaped spacers is readily possible by dis'engagingthe clamp members supporting the spacers.

What is claimed is:

1. An inductance coil support means comprising a coil having conductor turns, a plurality of insulating comb-shaped spacing members arranged to abut the conductor turns of said coil, a plurality of U-shaped clips for surrounding substantial portions of some of said conductor turns, a plurality of split clamp members each having means to engage the ends of said insulating combs and said clips, a coil support member, and clamping means for clamping said split clamp members to said coil support member.

2. An inductance coil support means comprising a coil having conductor turns, a plurality of insulating comb-shaped spacing members arranged to abut the conductor turns of said coil,

a plurality of U-shaped clips for surrounding substantial portions of some of said conductor turns, a plurality of split ring-shaped clamp members each having a projecting portion with slots for engaging the ends of said insulating comb-shaped spacing members and a portion of one of said U-shaped clips, a coil support member, and clamping means for securing said clamp members to said coil support member,

3. An inductance coil support means comprising a coil having conductor turns, a plurality of insulating comb-shaped spacing members arranged to abut the conductor turns of said coil, a plurality of .U-shaped clips for surrounding substantial portions of some of said conductor turns, a plurality of split ring-shaped clamp members each having a projecting portion with slots for engaging the end portions of one of said insulating comb-shaped spacing members and a portion of one of said U-shaped clips, a coil support rod, and slots located at right angles to correspond to said first mentioned slots for engaging the ends of said combs, and clamping means for securing said clamp members to said coil support rod.

4. An inductance coil support means comprising a coil having conductor turns, a plurality of insulating comb-shaped spacing members arranged to abut the outside coil portion of the conductor turns of said coil, a plurality of U- shaped clips having their closed portions located at the inside of said coil for surrounding substantial portions of some of said conductor turns, a plurality of split clamp members each having means to engage the ends of said insulating combs and said clips, a coil support rod, and clamping means for clamping said split clamp members to said coil support rod.

KURT FLACHOWSKY. 

